This application in a National Phase of PCT/JP99/04012 filed Jul. 27, 1999 and which claims the Paris Convention priority of the Japanese Application of Hei 10-251754 filed Aug. 3, 1998, the complete disclosure of which are hereby incorporated by reference.
1. Technical Field
The present invention relates to a transport-sort conveyor for sorting objects conveyed in a single file from a previous process step into a plurality of prescribed positions according to the object at some midpoint of transfer.
2. Background Art
Conventionally, a sort conveyor comprising a sliding block for pushing out articles sideways (to the side) onto a slat or a pipe roll that defines a conveying surface as a means for sorting articles on the conveying surface by providing sideward movement thereto, the sliding block having a guide pin projecting downwardly from the sliding block and a guide roller rotatably mounted thereto, wherein the articles are moved to specified positions (rows) or moved out sideward from the conveyor by lateral sliding movement of the sliding block along the slat or the pipe roll while being guided along the guide groove that allows the guide pin or the guide roller to move straight ahead and the sorting guide rail branched off said straight-ahead guide groove, as shown in Japanese Patent Publication No. 8-615, has been used.
Then, a switching guide rail (switching rail) is provided at a switching point of sorting (branch point) so that the guide pin of the sliding block is selectively guided into the straight ahead direction and the sorting direction by the operation of the switching guide rail. In such a switching mechanism, the switching operation is required when the pin of the sliding block passes over the switching point, and a slight time lag occurs due to elongation of the chain or the like. Therefore, there have been troubles such that the guide pins of the sliding block collide with a branch point between the straight-ahead direction and the sorting direction in the groove due to an insufficient sorting movement of the switching rail, and consequently, the pin is damaged or stopped by overrunning out of the groove. Therefore, attempt has been made to provide a spring at the position to which the pin collides to absorb shock, or to form a bevel to allow the pin to slide into any directions. However, the causes of the troubles have not been eliminated.
Since the conventional transport-sort conveyor as described above is provided at the switching point with a switching guide rail that diverts the pin projecting downward from the sliding block, in the case of the transport-sort conveyor for medium and small sized articles, of which the width of the bearing surface defining member such as a slat that defines the bearing surface is relatively small in the direction of travel, the interval between the pins of the front and rear sliding blocks is small, and thus when the speed of the conveyor is high, the switching mechanism cannot follow and the collision occurs as described above.
In addition, the length of the switching guide rail or the period of time required for performing the switching action limits the speed of the conveyor, thereby hindering the conveyor from increasing the speed. Especially, it has a disadvantage in that the length of the guide groove formed on the switching guide rail cannot be shortened due to the allowable diverting angle for smoothly introducing the pin of the sliding block advancing straight ahead from the upstream into the lateral sorting guide groove provided out of the straight-ahead path at the downstream end. In other words, there is a problem in that the interval distance between the sliding blocks cannot be shortened due to the required length for the switch rail.
In addition, since the switch mechanism is mounted on under the bearing surface of the frame, when a time lag occurrs between the sliding block and a sorting signal for the switching mechanism in association with elongation of the chain after long period of use, inspection or adjustment cannot be made easily.
Having resolved these problems, Japanese Patent Application No. 9-271872 was filed on Aug. 28th, 1997 for the present invention directed to a transport-sort conveyor suitable for a high-speed transfer sorting of the small sized articles. The object of the present invention is to provide a conveyor of further improved construction that can transfer and sort the smaller sized articles.
In order to achieve the object described above, the characteristics of the present invention are stated in the appended claims.
The invention comprises a transport-sort conveyor comprising a plurality of bearing surface defining members arranged in parallel, said bearing surface defining members being mounted at both ends on a conveyor chain endlessly rotating on a chain rail disposed on both left and right side, said bearing surface defining members being provided with a sliding block movable in the direction parallel with the bearing surface defining members, said sliding block having a pin projecting downward for being guided sideways from the sorting point along the guide rail so that the article on the bearing surface is sorted sideways, engaging means for engaging said sliding block to the conveyor on one side, said engaging means including an engaging strip and a holding portion on a part of a mounting member for mounting said bearing surface defining members onto said conveyor chain and on a part of said sliding block respectively, pusher means for urging said sliding block sideways in the sorting direction by a resilient member such as a spring provided on either one of said mounting member or said sliding block, an actuating device for releasing engagement between said engaging strip and a holding portion immediately before the upstream side of the sorting point, wherein said sliding block is urged by said pusher means in the sorting direction and moved sideways when the engagement between said engaging strip and a holding portion is released by said actuating device for allowing said guide pin projecting downward or a guide roller to travel toward the sorting path so that the sliding block is guided by the sorting guide rail provided from the sorting point in the sorting direction and moved sideways toward the discharging port.
The invention according to another embodiment is a transport-sort conveyor wherein a plurality of bearing surface defining members are provided on a pair of left and right mounting members, and a plurality of pusher means and engaging means corresponding to each mounting member and each sliding block are provided to make the mounting intervals of the sliding blocks shorter than the pitch of the chain link so that small sized articles can be sorted.
In another embodiment is a transport-sort conveyor further comprising an upper roller and an lower roller rotating while clamping the upper surface and the lower surface of the bearing surface defining member so that said sliding block moves smoothly in lateral direction by rotation of said rollers.
In another embodiment is a transport-sort conveyor wherein said engaging means comprises an engaging strip provided on said mounting member and a holding portion provided on said sliding block.
In another embodiment is a transport-sort conveyor wherein a pusher for urging said sliding block toward the sorting path is provided on a part of said mounting member.
In the invention each sliding block of the transport-sort conveyor is engaged with a mounting member on one side and the guide pin projecting downward or the guide roller travels along the straight-ahead path. When the bearing surface defining member having articles to be sorted thereon approaches to the sorting section and the sliding block reaches to the position immediately before the upstream side of the sorting point, the actuating device is actuated and releases the engagement between said sliding block and the mounting member, and the sliding block moves sideways toward the sorting path by being urged by the pusher means to travel along the sorting path. Since there is no obstruction such as a switching rail that limits the movement of the guide pin or the guide roller in the area where the guide pin or the guide roller moves away from the straight-ahead path toward the sorting path, the guide pin or the guide roller is positively and smoothly shifted to the sorting path immediately before the sorting point.
The actuating device actuates in accordance with the length of the article to be sorted in the direction of travel, and releases the sliding blocks corresponding to the side surface of the article from the leading edge to the trailing edge (sliding blocks translating together with the article) from engagement with each mounting member consecutively so as to move sideways from the straight-ahead path to the sorting path. The guide pin or the guide roller of the sliding block moved sideways toward the sorting path is guided by the sorting guide rail provided form the sorting point in the sorting direction to move the sliding bock sideways in the sorting direction in which a diverging conveyor Y is provided. The article loaded thereon is pushed sideways by the sliding block moving sideways and discharged toward the diverging conveyor Y to be sorted.
In another embodiment each sliding block of a plurality of bearing surface defining members provided on a pair of mounting member is independently engaged with the mounting member, and therefore, the dimension in the direction of travel of the mounting member calculated from the size of the chain link of the conveyor chain, that is, the mounting interval of the bearing surface defining member may be reduced to the length as short as a finger by dividing the same into a plurality of sections.
Therefore, it is suitable for the small sized sort conveyor for small sized articles that are desired to be sorted at small intervals about a length of a finger. On the other hand, even when a larger conveyor chain is used, the transport-sort conveyor in which a plurality of bearing surface defining member are arranged at a small intervals to a pair of mounting member can sort from large sized articles to small sized articles.
In addition, since the intervals of sliding blocks (mounting pitch) may be reduced, the sliding blocks corresponding to the length of the article from the leading edge to the trailing edge can be actuated for the sorting operation, sorting operation can be carried out without providing excessive space in front and behind the articles to be sorted. In other words, the article can be positively sorted even when they are not supplied and conveyed at regular intervals, but at random intervals.
In another embodiment since each sliding block is moved sideways while clamping the upper and lower surfaces of the bearing surface defining members by rollers constituted as door rollers, the pin projecting downward or the guide roller may be moved sideways smoothly without any strain when being guided by the sorting guide rail.
In another embodiment since the engaging strip and a pusher are provided on one of the mounting members fixed on the conveyor chain, the engaging strip and the pusher always travels stably so that the actuating device provided on the frame on the side of the conveyor ensures a release of engagement, thereby enabling a high speed operation.